An air carrier captain reported transitioning onto sfo taxiway a from taxiway B when the clearance w...

Attributes
ACN	1018770
Time
Date	201206
Local Time Of Day	1201-1800
Place
Locale Reference	SFO.Airport
State Reference	CA
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Large Transport Low Wing 2 Turbojet Eng
Operating Under FAR Part	Part 121
Flight Phase	Taxi
Person 1
Function	Captain Pilot Not Flying
Qualification	Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Last 90 Days 210 Flight Crew Total 25000 Flight Crew Type 11250
Events
Anomaly	Deviation - Procedural Clearance Ground Incursion Taxiway

Narrative:

Transitioned to inner taxiway [a] from outer at taxiway [B] prior to assigned taxiway due to misidentification of the taxiway we were on. What led up to the event was poor signage of the taxiways; radio congestion; sorting out a weight and balance issue. During the event we visually cleared the taxiways adjacent ramp areas prior to our turning onto them. The outcome of the event was successful transition to the inner taxiway. Due to the signage we didn't realize that we hadn't used the assigned taxiway until on the inner taxiway. The instructions were issued when we were practically at the assigned taxiway as it is very close to the taxiway we turned on.

Original NASA ASRS Text

Title: An air carrier Captain reported transitioning onto SFO Taxiway A from Taxiway B when the clearance was to use F1 because the signage at the the Taxiway A; B and F1 confluence did not clearly identify Taxiway F1 when approaching from the West.

Narrative: Transitioned to inner Taxiway [A] from outer at Taxiway [B] prior to assigned taxiway due to misidentification of the taxiway we were on. What led up to the event was poor signage of the taxiways; radio congestion; sorting out a weight and balance issue. During the event we visually cleared the taxiways adjacent ramp areas prior to our turning onto them. The outcome of the event was successful transition to the inner taxiway. Due to the signage we didn't realize that we hadn't used the assigned taxiway until on the inner taxiway. The instructions were issued when we were practically at the assigned taxiway as it is very close to the taxiway we turned on.

Data retrieved from NASA's ASRS site as of July 2013 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.

An air carrier captain reported transitioning onto sfo taxiway a from taxiway B when the clearance was to use F1 because the signage at the the taxiway a; B and F1 confluence did not clearly identify taxiway F1 when approaching from the west.